The smell from hell wafting from La Jolla Cove is now — hopefully — a blast from the past.

That is the hope of public officials who sanctioned spraying of microbial foam to eradicate foul odor from cliffs surrounding La Jolla Cove.

The first phase of cliff spraying was completed after 10 days of work on June 28.

Cove cliffs have become so saturated by bird excrement that they’ve been declared an economic, health and safety emergency by Mayor Bob Filner.

Filner held a press conference June 17 to kick off Cove cleanup, then followed that up with a June 28 news release, in which he said the city’s contractor, Blue Eagle Distribution, Inc., has been able to “substantially reduce odors related to bird guano deposits and has set the stage for an even more extensive second phase of the cleanup effort now set for early August.”

“This is a great success,” Filner said. “The odor is down and fun is back up in La Jolla.”

The worsening smell of bird waste after years of build up at the Cove, heightened especially during the warmer summer tour- ist season, has led to growing unrest from residents and businesses in the area demanding public officials take action to quench the stench.

Bill Harris, the city’s supervising public information officer, said Blue Eagle crews “inched their way along the cliff face, applying the anti-odor material such that it did not run into the ocean, and in such a quantity as to have an impact on the odor.”

Harris described the odor-fighting product being used by Blue Eagle as “a collection of non-pathogen bacteria that digests the microbial fungus and chemicals that create the odor and the build up of guano.”

The city’s spokesman said the cleansing foam has proven results.

“It not only attacks those things that are stinky, but also has the benefit of reducing the thickness of the guano,” Harris said, adding the active organic foam ingredients “die and don’t have any discharge into the water at all.”

Keith Merkel of Merkel & Associates, Inc., a marine biologist consulting the city on Cove cleanup, said odor eradication in the cliff area between the Cove and the Clam is being done in two phases this summer.

“Phase one is constrained by nesting birds, working around them covering all the areas we can without causing abandonment of nesting,” Merkel said. “Then we’ll wait until nesting is finished the end of July or early August, and spend another 10 days cleaning the areas we couldn’t get to before.”

The results of the odor-eradication effort will be monitored to measure its effectiveness. What long-term strategy is to be employed afterward to preserve the status quo will then be determined.

“[Spraying] would have to be done two or three times a year,” Merkel said, adding there’s a lot of uncertainty as to how effective the spraying will be — or how long it will last.

“This has been several years in the making and the birds aren’t going to stop crapping on the rocks. It will continue,” he said.

Filner declares Cove cleanup a successThe smell from hell wafting from La Jolla Cove is now — hopefully — a blast from the past. That is the hope of public officials who sanctioned spraying of microbial foam to eradicate foul odor from...